Abstract: In this paper,we present an overview of various aspects of the self-assembly of organic monolayers on silicon substrates for molecular electronics applications.Various theoretical models,namely,tunneling（direct and Fowler-Nordheim）,thermioic emission,Poole-Frenkel emission and hopping conduction have been outline.Finally,the concepts and realization of various molecular electronic components,that is,diodes,resonant tunnel diodes,memories and transistors,based on appropriate architecture of self-assembled monolayers（SAMs） comprising of alkyl chains（σ-molecule） and conjugated molecules（π-molecule） have been presented too.